Cheat Sheet: Exactly When You Need to Replace Your Makeup

Since the action of taking the brush in and out of the tube increases the amount of bacteria introduced to the product, mascara tends to have a relatively short shelf life. Said bacteria is nothing to sneeze at: "When you use makeup after the expiration date, you are exposing yourself to bacterial overgrowth, contamination, infection and other toxins," says Stoj. Besides, you'll also likely notice the formula growing clumpier and more difficult to use over time, which definitely makes your decision to ditch your favorite tube a little easier.

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